Accept empty strings for log_dir

An empty string is an acceptable value of this entry, and it forces
logging to stdout/stderr, which is useful when running on containers.

Change-Id: I79a53d59f948c19b22f883d120e1afed7439d643

manifests/logging.pp

@@ -111,7 +111,11 @@ class ironic::logging(
   $use_syslog_real = pick($::ironic::use_syslog,$use_syslog)
   $use_stderr_real = pick($::ironic::use_stderr,$use_stderr)
   $log_facility_real = pick($::ironic::log_facility,$log_facility)
-  $log_dir_real = pick($::ironic::log_dir,$log_dir)
+  if $log_dir != '' {
+    $log_dir_real = pick($::ironic::log_dir,$log_dir)
+  } else {
+    $log_dir_real = $log_dir
+  }
   $debug_real = pick($::ironic::debug,$debug)
 
   oslo::log { 'ironic_config':

releasenotes/notes/accept-empty-strings-log-dir-fc9ebec7543ea3a5.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    It is now possible to pass empty strings to the log_dir option. This enables
+    logging to stdout/stderr.

spec/classes/ironic_logging_spec.rb

@@ -31,6 +31,13 @@ describe 'ironic::logging' do
     }
   end
 
+  let :empty_log_dir_param do
+    {
+      :log_dir => '',
+    }
+  end
+
+
   shared_examples_for 'ironic-logging' do
 
     context 'with basic logging options and default settings' do
@@ -51,6 +58,11 @@ describe 'ironic::logging' do
       it_configures 'logging params unset'
     end
 
+    context 'with empty log_dir' do
+      before { params.merge!( empty_log_dir_param ) }
+      it_configures 'empty log dir'
+    end
+
   end
 
   shared_examples 'basic default logging settings' do
@@ -110,6 +122,14 @@ describe 'ironic::logging' do
       }
   end
 
+  shared_examples 'empty log dir' do
+    it 'configures ironic logging with empty log dir' do
+      is_expected.to contain_oslo__log('ironic_config').with(
+        :log_dir => '',
+      )
+    end
+  end
+
   on_supported_os({
     :supported_os => OSDefaults.get_supported_os
   }).each do |os,facts|